Dietary Supplement, which is translated as “health supplement” or “nutritional supplement”, is ingested mainly to supplement nutritional components such as vitamin, mineral, and amino acid which are apt to be scrimpy in everyday life (hereinafter, may be referred to “supplement”, “health supplement” or “nutritional supplement”). In the U.S., there are laws about supplements, and supplements are positioned as a new genre different from both foods and pharmaceuticals, and have been approved to label with a Health Claim of the activity to reduce the risk of diseases.
Analysis of in vivo migration of an administered substance to a living body, which is usually executed by determining contents such as blood level and urine level, needs specimen collection executed by a specific facility such as a medical institution. Therefore it has been difficult to analyze in vivo migration of a nutritional component contained in a nutritional supplement or the like according to the convenience of a subject.
Saliva may also be a specimen but has inadequate to use as a specimen for a method for analyzing in vivo migration of a nutritional component contained in an ingested health supplement. It is partly because a method for collecting specimen has not been established to give a reproducible value.
Ubidecarenone (CoQ10), which is a nutritional component comprised in the nutritional supplements and constantly presents in mitochondrias, is a coenzyme involved in energy production in which ADP is converted to ATP by oxidation from a reduced form of ubidecarenol to an oxidized form of ubidecarenone (CoQ10) in the electron transport system. In a living body, CoQ10 is not present in the blood, but mainly in the tissues, and about 90% of CoQ10 is present as a reduced form in cell membranes and phospholipid double membranes in organelles. The CoQ10 can be synthesized through enzyme reactions in common with the cholesterol biosynthesis pathway in a human body, therefore its synthesis is supposed to be inhibited in a patient treated with a statin base drug although it is not a vitamin (Proc Natl Acad Sci. USA, 1990 November; 87: 8931-4, Lovastatin decreases coenzyme Q levels in humans, Folkers K, Langsjoen P, Willis R. Richardson P, Xia L J, Ye C Q, Tamagawa H.). A Statin base drug with higher lipophilicity is supposed to have higher degree of inhibitory potency against the synthesis, and ingestion of CoQ10 is considered to be useful for avoiding the adverse effects by the drug. Clinical trials by its combination therapy have been already performed in the U.S.
Tocopherol (vitamin E), which is a nutritional component comprised in the health supplements, is a major substance to prevent a lipid radical from oxidation, because tocopherol radicals collides with each others to eliminate the radical. A large abundance of tocopherol lowers incidence of collision among the radicals to cause the radical to remain longer. However, a reduced form of CoQ10 in vivo is believed to be potently associated with the tocopherol radicals to eliminate the radical.
Meanwhile, in the developed countries, the mortality rate in myocardial infarction and cerebral infarction potentially resulting from arteriosclerosis is being increased, and the number of diabetics potentially resulting from the lifestyle is rising, and in Japan, diabetes is tops in the novel pathogenesis resulting in hemodialysis patients.
These so-called life-style related diseases are considered to be strongly affected by dietary habit and strongly involve increased oxidative stress in vivo, therefore aggressive ingestion of a substance against oxidative stress is recommended as nutritional supplements. However, a so-called non-patient, who is not at a stage to visit a hospital, loses a chance to receive health management by a doctor to fall in a worsened symptom before visiting the hospital. This too late treatment may contribute to increased number of patients.
There has been no report about concentrations and contents of fat-soluble vitamins such as tocopherol or of fat-soluble food factors such as CoQ10 or lycopene found in saliva and salivary gland associated with salivation. It may be because saliva levels of a vitamin impossible to synthesize in a human body and a so-called supplement capable of being ingested by diet are easily assumed to be influenced by amount and sort of the foods and drinks left in the oral cavity, the existing substances derived from various bacteria and fungi, and additionally plaque bacteria flora on the surface of a tooth.
In addition, although fat-soluble β-carotene which is a provitamin of vitamin A has been known to show a positive correlation between the serum level and the whole saliva level (for example, refer to Nonpatent documents No. 1 and 2), the object of the reporters in Nonpatent documents No. 1 is “to confirm and verify assumption that an ingested β-carotene is useful for maintenance of oral hygiene by enhancing production and secretion of an antibacterial protein such as glycoprotein or lysozyme in the salivary gland”, but not to assess levels of in vivo migration of β-carotene. The reporters in Nonpatent documents No. 1 report that β-carotene in the parotid saliva could not be detected. Thus it is significantly meaningful if it would get verified that β-carotene can be detected from saliva or even parotid saliva, and that saliva is a biological sample suitable for analyzing fat-soluble vitamins and/or fat-soluble food factors. Furthermore, it is particularly significant to provide a method for analyzing and inspecting fat-soluble vitamins and/or fat-soluble food factors in saliva.
Nonpatent document No. 1: Int. J. Vitam. Nutr. Res. 1988; 58(2): 171-7 Saliva concentrations of some selected proteins and glycoprotein markers in man after supplementary intake of beta-carotene. Lumikari M. Johansson I., Ericson T., Virtamo J.
Nonpatent document No. 2: Nutr. Cancer 1988; 11(4): 233-41 Effects of excess vitamin A and canthaxanthin On salivary gland tumors. Alam B S, Al am SQ, Weir J C Jr.